Characteristics of new particle formation events and cluster ions at K-puszta, Hungary

Atmospheric new particle formation events were analyzed based on particle size distributions measured with a Differential Mobility Particle Sizer (DMPS) and an Air Ion Spectrometer (AIS) during the BIOSOL (Formation mechanisms, marker compounds, and source apportionment for biogenic atmospheric aerosols) campaign on 22 May-29 June 2006 at the K-puszta measurement site in Hungary. The particle size distribution data were classified into different new particle event classes and growth and formation rates of the particles were calculated. New particle formation was observed on almost all days and the median diameter growth rates of nucleation mode particles increased with increasing particle size. The observed formation rate of 10 nm particles was typically somewhat larger than 1 cm(-3) s(-3) (median 1.2), and the growth rate for sub 3 nm particles was 1.7 nm h(-1) and for nucleation mode 6 nm h(-1). The ambient concentrations of gases or meteorological data were not able to explain the differences in the growth and formation rates or in the particle formation between the days. However, 0.3-1.8 nm cluster ion concentrations correlated negatively with wind speed.